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Software Vault: The Gold Collection
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Software Vault - The Gold Collection (American Databankers) (1993).ISO
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cdr11
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powerb5.zip
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CHECK_ID.BAS
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BASIC Source File
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1993-06-01
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733b
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31 lines
'Program CHECK_ID.BAS
DECLARE SUB CheckID (ID$, Flag%)
Flag% = 0
DO UNTIL Flag% = 1
INPUT "Enter ID Number: ", ID$
CheckID ID$, Flag%
IF Flag% = 0 THEN
PRINT "Invalid ID number! Re-enter: "
END IF
LOOP
PRINT "ID number "; ID$; " is valid."
SUB CheckID (ID$, Flag%)
' Set Flag% to 1 if ID$ contains a
' valid 6-digit ID number. Otherwise,
' set Flag% to zero.
DIM D(6) AS INTEGER
Flag% = 0
IF LEN(ID$) <> 6 THEN EXIT SUB
FOR I% = 1 TO 6
A$ = MID$(ID$, I%, 1)
IF A$ < "0" OR A$ > "9" THEN EXIT SUB
D(I%) = VAL(A$)
NEXT I%
'Calculate last digit from first 5
Check = D(1) + D(2) * 2 + D(3)
Check = Check + D(4) * 2 + D5
Check = Check MOD 10
IF Check = D(6) THEN Flag% = 1
END SUB